Does Apache OFBiz delegator API support fetching list of records from database by limit or offset
Let's say we have to fetch only 5 records from a table but my where clause is matching 25k records in the database. So is there a way in ofbiz
framework to just select 5 records rather than getting a list from the database and then taking just 5 from the list?
If the limit is not possible (since ofbiz
API is database agnostic) what are 开发者_开发问答my other alternatives?
I would suggest you take a look into this entity engine cookbook
Essentially for getting limited set of rows from database you would do:
// first get a list iterator
productsELI = delegator.findListIteratorByCondition("Product",
new EntityExpr("productId", EntityOperator.NOT_EQUAL, null),
UtilMisc.toList("productId"), null);
// then get a partial list by count TO RETURN first 5 records
productsELI.getPartialList(0, 5);
// and finally just close the iterator
productsELI.close();
Also if you prefer to send direct SQL to your database then just do like this:
// gets the helper (localmysql, localpostgres, etc.) for your entity group org.ofbiz
String helperName = delegator.getGroupHelperName("org.ofbiz");
SQLProcessor sqlproc = new SQLProcessor(helperName);
sqlproc.prepareStatement("SELECT * FROM PARTY LMIT 0, 5");
ResultSet rs1 = sqlproc.executeQuery();
// and then get your data from ResultSet like regular JDBC
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